With the increasing use of semiconductor chips in industry, automated processing of such chips on a customized basis has become important. Processing chips using lasers has become a more widely used practice. To precisely draw lines onto a semiconductor die using a laser, it is best to keep the surface being drawn on orthogonal to the laser beam. This ensures that the lines will be of a constant width. If the lines should vary in width by as little as a micron, the finished chip may be of little or no use. Likewise, it is important that other electronic devices be kept level when detailed work is performed on them.
While other methods of leveling electronic components are known, the present invention provides a versatile and accurate method of leveling workpiece. One such previous method involves blowing air onto different parts of the surface to be leveled and then sensing the reflected air flow. This method proves to be too imprecise for controlling the leveling of small devices. Another method is to measure the capacitance of the device to be leveled at areas far apart from one another. For large, smooth pieces of equipment such as photomasks for chips, this method has proven itself to work, but for small electronic devices whose topography is rough, this method is ineffective. Devices that are less than 1/4 inch on a side are too small to utilize this method effectively.
It is obvious that what is needed is an apparatus adaptable to both large and small surfaces areas as well as surfaces that vary in topography. Such apparatus should be programmable for any type surface and be able to level components as small as IC's.